I’ve actually already finished the flap completely and have blocked the pieces. However, the camera is in the shop, so I can only show part of the progress I’ve made.
After cutting the front and back apart (by cutting through the steek), I picked up the flap stitches on the back half and then knitted the flap using intarsia, which is a different color knitting technique than the other parts of the bag required. You can see the difference from the wrong side of this piece.
The blue and purple part has the yarn running all the way across the stitches in the back, which is necessary, because the two colors in any one row are used constantly. This type of stranded color work is also known as Fair Isle knitting. The pink and blue part has large areas of a single color, so a single strand of yarn is worked for a single motif (i.e., one strand of blue for each separate rose), which is intarsia. Both techniques require counting and careful yarn management, but I think it is worth the extra effort to have more color in the piece.
The next step, which I will post when I have a picture of it, uses duplicate stitch, which is actually embroidery rather than knitting.